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June 2002

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TechNet <[log in to unmask]>
X-To:
Bev Christian <[log in to unmask]>
Date:
Thu, 20 Jun 2002 14:52:56 -0700
Reply-To:
"TechNet E-Mail Forum." <[log in to unmask]>, David Douthit <[log in to unmask]>
Subject:
Re: cracks in solder joints
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From:
David Douthit <[log in to unmask]>
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Bev,

In the spirit of generalities my answer would be "if you can detect it, it is too big!"

The end of the crack is a major stress concentration point and will propagate rapidly.
Of course if you wait a few more cycles the crack will get really big and then it is definitely "big
enough".

A better question would be how do you distinguish between a crack and a void?

David A. Douthit
Manager
LoCan LLC

Bev Christian wrote:

> Hopefully this will start off a nice discussion.  I have kept it general for
> that purpose.
>
> Shades of voids in BGAs...   How big of a crack in thermally cycled solder
> joints is too big of a crack?
>
> Bev Christian
> Research in Motion
>
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